The present invention relates generally to apparatus for well completions, and in particular, to apparatus for isolating distinct zones from each other in a well bore.
In completion of a well bore for oil, gas, or the like, it is often desired to perform certain completion operations in a particular zone of the well bore, such as gravel packing, acidizing, or the like. After completion of one of these operations, it is often necessary to protect the structure in which the operation was performed by isolating the zone in which the operation was performed from other zones of the well bore during completion operations of the other zones. However, after operations in the other isolation areas of the well bore have been completed, it is necessary to open the isolated area to complete the well bore. Therefore, there is a need for apparatus and methods for isolating a zone of the well bore that can be re-opened for final completion of the well bore.
Completion of the well bore can be affected by the type of debris that is created within that well bore. Therefore, there is a need for apparatus and methods of isolating particular zones in a well bore that reduce the amount of debris that negatively influences the completion of the well bore.
Before a zone is isolated in a well bore, it may be necessary to draw fluids from the zone to be isolated through any device that is later used to isolate the particular zone. Fluid flow through an isolation device, prior to use of the device to isolate a particular zone, may be at high flow rates. Therefore, there is a need for apparatus and methods which allow high fluid flow to and from the zone to be isolated, prior to isolating that particular zone.